Lijun Cao

Notice of Retraction Decision-making model for ranking battlefield damaged equipment repairs based on multi-criteria

By analyzing and quantifying the ranking principles for the urgent repair of battle-damaged equipment, a mathematical model using fuzzy synthetic judgment (FSJ) is established. The problem of decision-making concerning the ranking of multi-equipment repairs by multi-criteria is solved and a basis for decision-making is provided for the equipment support authoritative department. It is expected to provide the calculating and simulating tools to optimize maintenance force deployment for equipment support directors and improve the fact that equipment commanders decide the urgent repairing order depending on one principle or experience.

The Signal Extraction and Compression of Engine Rotate Speed of a Certain Type of Chassis

For the diesel engine of a certain type of chassis, the key task to be solved in special vehicle technical support is fault diagnosis technology. In terms of fault diagnosis of a diesel engine, fault signal extraction is always needed no matter what methods are adopted. There is no accurate diagnosis decision without an effective extraction method. Aiming at finding fast and effective fault diagnosis to a diesel engine without vehicle disassembly, the authors explore into detection signal during the diagnosis and study extraction and compression of rotating signal in the paper.

Service life forecast and evaluation of transmission system for Complicated equipment

Transmission system is the key subsystem of Complicated equipment to realize its maneuverability. Statistic data show that 36 percent of chassis faults is caused by transmission system. To overcome the difficulties of battle decision in confirming appropriate maintenance periods and allocating maintenance resource, a new kind service life and evaluation method based on virtual prototype and Finite Element Analysis (FEA) is put forward firstly. The three-dimensional solid models of transmission system is established and assembled in Pro/E. By adding relevant forces and constraints, the working and fault emergence and development processes are simulated in MSC.ADAMS. The FEA models of key components are established in MSC.Patran and FE-FATIGUE. On the basis of simulation results of virtual prototype and FEA analysis results, the service life of key components of transmission system can be calculated.

Fault diagnosis research on gun chassis engine based on the burning gas pressure

Modern self-propelled artilleries compose weapons parts and chassis parts. Its chassis is walking part of self-propelled artilleries and the chassis engine is the heart of the walking part. Technical state of the engine directly influences the condition of artillery technology. Thus, the research on fault diagnosis of the chassis engine of artilleries is very important. Fault diagnosis of the engine of artillery chassis based on gas pressure are analyzed and researched in this paper.

Load spectrum measurement and fatigue life prediction of torsion shaft of self-propelled guns

In order to predict the fatigue life of torsion shaft of self-propelled gun, an experiment has been carried out through field test to achieve the load spectrums of torsion shaft. The conclusion that the maximum tensile stress is the failure stress of torsion shaft is drawn. The stochastic response surface method (SRSM) is introduced to study the low cycle fatigue life of torsion shaft. The stochastic parameters of low cycle fatigue life are expressed to stochastic variables, and the structural stochastic response is fitted based on Hermite polynomials. The function of the low cycle fatigue life of torsion shaft is achieved. The results show that the SRSM can achieve the statistical information of the structural stochastic response rapidly and accurately.

Analysis and simulation of stochastic fatigue reliability for running system of complicated equipments

Actual equipment experiments are adopted to measure the load spectrum of torsion shaft. Virtual prototyping supplement the load spectrum that cannot be measured by actual experiments. The comparison and analysis between actual vehicle experiment data and virtual test results of virtual prototype verify their complementarities, which provide full and accurate load spectrums for the key components. Combined with materials S-N curve, stress and strain spectrums can be obtained. To analyze the stochastic fatigue reliability accurately, nominal stress method and local stress and strain method are combined with probability density accumulation damage theory to compute the probability density distribution function. The computational results of stochastic fatigue reliability provide sufficient reference for determination of appropriate maintenance cycle and prediction of running system reliability.